www.invasive.org.At least 4,500 non-native plants and animals, including 185 species of fish and 88 species of mollusks, have been established in the United States. The number of exotics here has increased in recent years because of the activities of humans.
Some of these exotics have been welcomed with open arms. For example, people are usually surprised to learn that both rainbow trout and brown trout are non-native to the Connecticut River basin. These fish provide a wonderful recreational fishery and are considered very desirable among anglers.
The problem is that many, if not most, of these new comers have no natural predators, so they can spread and grow at an alarming rate. Through that process, they have the potential to crowd out native species, disrupt local ecology, and sometimes threaten human health. For more information on invasive species, please visit www.invasive.org.
Aquatic nuisance species are one key factor contributing to the growing number of threatened and endangered fish and freshwater mussels. Nationally, 115 species of fish are listed as endangered, including the Connecticut River's shortnose sturgeon. Almost 72% of the freshwater mussels in the United States are endangered, threatened or of special concern. This includes the watershed's dwarf wedge mussel.
Sometimes aquatic nuisance species have other unexpected negative impacts on the economy. The cost of control and management can be astronomical once an infestation has occurred, as is the case with the zebra mussel in the Great Lakes. As a consequence of all of these concerns, Congress passed the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 (Public Law 101-646) to prevent and control infestations.
For these reasons, the U.S. Fish and Wildlife Service and many other groups and agencies, are actively working to educate, prevent, monitor and control aquatic nuisance species. Locally, the New England Invasive Plant Group has a news briefing mailing list - get more information at http://invasives.eeb.uconn.edu/mailman/listinfo/nipgro-announce. This service will keep you updated on workshops, events and current happenings in this field.
Water Chestnut is a rooted, aquatic plant with both floating and submersed leaves. The floating leaves form a rosette and are green, glossy and triangular with toothed edges. The submersed leaves are feathery, and are found whorled around the stem. Plant stems are cord-like and can attain lengths of up to 16 feet. Water chestnut is an annual plant, overwintering entirely by seed. In July the plant begins to produce seeds (called nuts) with 4 sharp spines. Mature seeds are green to greenish brown and sink to the bottom. Seeds may remain alive in the sediment for up to 12 years! Floating black nuts will not sprout. (Please note: this plant species is not the same as the "water chestnut" used in Asian cooking.)
Shallow (< 16 ft) areas of freshwater lakes and ponds, and slow-moving streams and rivers.
Water chestnut's native range is Europe, Asia and Africa. Since its introduction into North America in 1877, it has become a nuisance species because of its ability to reproduce rapidly and form dense floating mats. Water chestnut is presently found in Massachusetts, Vermont, Connecticut, New York, Pennsylvania, Maryland and Virginia. Within the Connecticut River watershed, water chestnut is found in Massachusetts and Connecticut in a few coves, ponds and an impoundment. The seeds, or severed plant parts carrying seeds, may drift downstream. Ducks and geese may also be responsible for the plants dispersal. Canada geese have been seen with the spiny nuts attached to their feathers.
Early detection is the key to control since smaller populations are easier to eliminate than larger ones. It also costs less to control a small infestation because plants can be individually hand-pulled. Large populations require the use of mechanical harvesters or application of aquatic herbicides to achieve control. Infested waters must be treated for 5-12 years to eliminate the invading population. However, some infestations are so extensive (e.g. >300 acres in Lake Champlain) that complete eradication may never be achieved. Many states, including Massachusetts, New Hampshire, South Carolina, Florida, New York and Arizona, have adopted laws to prohibit the intentional distribution of this aggressive plant.
View the water chestnut profile at www.invasivespecies.gov/profiles/waterchestnut.shtml.
You will need Adobe Reader software to open some of the documents below. If you do not have this software, you may obtain it free of charge by following this link.
Water Chestnut Fact Sheet (237 KB Adobe pdf file)
Water Chestnut Survey Form (22 KB Adobe pdf file)
Water Chestnut Management Form (25 KB Adobe pdf file)
Zebra mussels look like small striped clams. They were first introduced in the Great Lakes in 1986 and have spread through the Great Lakes and the Ohio and Mississippi Rivers. They have not been found in the Connecticut River watershed yet but they have been found in Lake Champlain and in the Hudson River basin. They attach to solid objects in freshwater, clogging water intake pipes and fouling the bottoms of boats. They harm the natural ecology of waters that they infest. The zebra mussel can be spread by people, boats and bait. Look out for these critters, and notify us if you think you have seen them in the watershed. For more information, visit the following Web site: www.invasivespecies.gov/profiles/zebramussel.shtml.
U.S. Fish and Wildlife Service